KANSAS CITY, Mo. — It’s been nearly 10 months since Alex Smith started a game in the NFL.

In between, the quarterback of the Kansas City Chiefs sustained a concussion, had his job in San Francisco ripped from his hands, watched from the sideline as the 49ers marched to the Super Bowl, was traded halfway across the country and forced to start all over with a new head coach.

So to say Smith has been counting down the days until he leads the Chiefs onto the field Sunday in Jacksonville would be an understatement. In reality, he’s been counting the seconds.

“It’s tough to put into words,” he said. “From about mid-season last year, I was thinking about where my next opportunity was going to come and when this presented itself, I jumped at it and now it’s here. The season is here, week one is here and this is what we’ve been working for.”

It’s not like taking the game’s first snaps will be a novel concept. Smith started seven games as a rookie for San Francisco in 2005. He started all 16 games the following year.

In fact, by the time Smith was traded to the Chiefs for a pair of draft picks this past offseason, he had started 75 of the 80 games he had played with the 49ers. That included every game two years ago, when he went 13-3 and led them to the NFC championship game.

Still, it’s been a while since Smith took the opening snap in a game that counted.

“I don’t think taking a game off is going to affect a guy like Alex. He’s started a lot of games in the NFL,” Chiefs offensive coordinator Doug Pederson said. “He knows how to handle an opening day, and he’s started his preparation for this game weeks ago. He’ll get himself ready to go.”

The last time Smith made a start was Nov. 11, 2012, against St. Louis. It was in that game that Smith sustained a concussion. He threw a touchdown pass in an eventual 24-24 tie despite some blurry vision, and then was pulled from the game a short while later.

Smith didn’t play the following week as Colin Kaepernick made his debut, and then 49ers coach Jim Harbaugh elected to stick with the younger quarterback for the remainder of the season.

At one point, Smith said he felt like he lost his starting job without doing anything wrong, and he later said he wanted to “stick it” to his detractors. It was assumed that Harbaugh was among them, but Smith said he was merely speaking in generalities. The message was obvious nonetheless: The former No. 1 overall pick is once again playing with a chip on his shoulder.

“For me it’s going to be about getting the win. That’s all I’m thinking about,” Smith said this week, downplaying his first regular-season start since last November. “Playing good football, playing smart football, I think that’s what puts you in position to win games.”

Several teams that expressed interest in trading for Smith, but he made it clear in March that Kansas City was his preference. He was intrigued by playing for Andy Reid, who’d tried unsuccessfully to trade for him during his years coaching the Eagles, and the possibility of quickly turning around a 2-14 franchise that featured six Pro Bowl players was alluring.

Once the traded for Smith was made, the Chiefs started to build around him.

They made sure wide receiver Dwayne Bowe was happy by giving him a new deal, and then signed free agent wide receiver Donnie Avery. They upgraded at right tackle by drafting Eric Fisher first overall, signed veteran tight end Anthony Fasano and drafted another tight end in Travis Kelce.

Now, it’s up to Smith to make sure all the pieces work.

“They don’t need to do anything other than execute the offense and do what they do best, let their personality show and play the game,” Reid said. “I’m speaking for all of them, but at the same time, that’s what I expect from Alex, too.”

If that happens, the Chiefs just might get their season off to a winning start.

“That’s all we’re talking about and what the focus has been,” Smith said. “Especially a team with a lot of new faces and a new coaching staff, coming together and reinforcing what we’ve done by getting that first win, it would mean a lot.”

Notes: DB Husain Abdullah (left foot) and OG Jon Asamoah (right calf) did not practice. LB Nico Johnson (right ankle) took part in individual workouts that the media was allowed to see. ... Special teams coach Dave Toub said WR Dexter McCluster will be the primary punt returner. DB Quintin Demps will handle most kickoffs with Davis possibly getting an opportunity.